Photographic desensitizing



Patented Oct. 4 1938 UNITED STATES PATENT OFFlCE PHOTOGRAPHIC DESENSITIZING Karl Kumetat, Dessau, and Sebastian Gassner, Leverkusen, near Cologne, Germany, assignors to Agfa Ansco Corporation, Binghamton, N. Y., a corporation of New York No Drawing. Application March 3, 1937, Serial I No. 128,824. In Germany October 11, 1935 9 Claims.

Our present invention relates to photographic desensitizing. I

One of itsobjects is a photographic desensitizing bath. Another object'is'a desensitizing process for light-sensitive photographic materials. Another object are the desensitizers. Further objects will be seen from the detailed specification following hereafter.

This invention is a continuation in part of our application Ser. No. 104,442 filed Oct '7, 1936. That application relates to a process for desensitizing light-sensitive silver halide emulsions by.

use of the unsubstituted and alkylated taurides of anthraquinone-carboxylic acids and/or sulfonic acids.

This invention is based on the observation that there are also useful as desensitizers instead of' the aforesaid substances other acid amides of the anthraquinone series in which at least 1 hydrogen atom of the amide-group is replaced by a residue containing a sulfonic or carboxylic acid gram -When only 1 hydrogen atom ofltheamide 'group is thus replifia'd'the other hydrogen atom may also be replaced by any other organic residue, for example an alkyl or aryl residue. For example the amino group may be substituted as follows:'

Glyeocoll Sarkosino N-oni-coon Phenyglycinc atomomsom Phonyltaurine 1 soin v oon I Substances suitable for in the invention 50. are, for instance, the sarcosides of-the anthraquinone-carboxylic acids and anthraquinone-sulfonic acids, for example the compounds of the formulae:-

in-this solution, after yvhichstheymafbe developed in the bright-green light.

(2) 0.75 gram of the sodium salt of anthraquinone-2-carboxylsarcoside,and 25 grams of anhydrous sodium 'sulfit'e" are dissolved in 1 litre of- W Water The photographic layers are bathed for 2' minutes in this solution, after which they may be developed in the bright-green light. r

(3) Ortho-chromatic and panchromatic photographic layers are developed in l litre of a developer of the following composition:

1 litre ofwater, v I 8 grams of 1-hydroxy-4-methylaminobenzenesulfate, l

125 grams of anhydrous sodium sulfite,

5.8 grams of anhydrous so'dium carbonate;

-2.5 grams of potassium bromide, v

0.4 gram of the sodium salt of anthraquinone-2- sulfopheny'lglycide.

I 4)' Ortho-chromatic and panchromatic photocarboxyl group.

2 graphic layers are developed in one litre of a developer of the following composition:

1 litre of water,

8 grams of l-hydroxyi-methylaminobenzenesulfate,

125 grams of anhydrous sodium sulfite.

5.8 grams of anhydrous sodium carbonate,

2.5 grams of potassium bromide,

0.75 gram of the sodium salt of anthraquinone- 2- sulfophenyltauride.

What we claim is: a

1. A process of ,desensitizing a light-sensitive silver halide emulsion which comprises treating said silver halide emulsion with a compoundselected from the group consisting of N-aryltaurides and amides of one of the group consisting of anthraquinone carboxylic acids andv 2. A process of desensitizing a light-sensitive silver halide emulsion which comprises treating said silver halide emulsion with a compound selected from the group consisting of N-aryltaurides and amides of one of the group consisting of anthraquinone carboxylic acids and anthraquinone sulfonic acids, said amides being selected from the group consisting of amides the nitrogen of which is linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, amides the nitrogen of which is directly attached to an aryl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group and amides the nitrogen of which isdirectly attached toan alkyl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl gi'oup, and with an alkali sulfite.

w 3. 'A process of desensitizing a light-sensitive silver halide emulsion which comprises immersing said silver halide emulsion'befin e development in a preliminary bath containing a com- -To llndkselected from the group consisting of N-arylta uridesmnd 'amides of one of the" group a l fl iultl'mckafiidsrsaldjmldes being Selected amidewgogen of which is linked to a radical selecte iii-- consisting of anthraquinone carboxylic acids and anthraquinone sulfonic acids, said amides being selected from the 'group co iisting of amides the nitrogen of which is linked to araidiealsficted from aliphatic and aryl radicals containing w carboxyl group, amides the nitrogen of which is directly attached to an aryl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, and amides the nitrogen of which is directly attached to an allcyl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group.

- 4. A process of desensitizing a light-sensitive silver halide emulsion, which comprises immersing said silver halide emulsion before development in a preliminary bath containing a compound selected from the group consisting of N-aryltaurides and amides of one of the group consisting of anthraquinone carboxylic acids and anthraquinone 'sulfonic acids, said amidm being aryl radicals containing a carboxyl group, amides 18/ selected from the group consisting of amides the nitrogen of which is linked to a radical selected from aliphatic and aryl radicals containing a. carboxyl group, amides the nitrogen of which is directly attached to an aryl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group and amides the nitrogen of whichis directly attached to an alkyl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, and an alkali sulfite.

5. A process of desensitizing a light-sensitive silver halide emulsion, which comprises develop- 'ing said silver halide emulsion in a bath containing developing agents and a compound selected from the group consisting of N-aryltaurides and amides of one of the group conanthraquinone sulfonic acids, said amides being selected from the group consisting'of amides the nitrogen of which is linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, amides the nitrogen of which is directly attached to an aryl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, and amides sisting of anthraquinone carboxylic acidsand,

the nitrogen of which is directly attached to consisting of amides the nitrogen of which is' linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, amides the nitrogen of which is directly attached to an a yl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, and amides the nitrogen of which is directly'attached to an alkyl radical and linked to a a radical selectTfiom aiiphatiaand arylsradicals containing a carboxyl group, and an alkali sulfite.

I. A bath for desensitizing 'a light-sensitive silver halide emulsion comprising a compound selected from the group consisting of N-aryltaurides and amides of one of the group consisting of anthraquinone carboxylic acids and anthraffdhfthe' group consisting of phatic and aryl radicals containing a carboxyl group, amides the nitrogen of which is directly attached to an aryl radical and linked to a radical selected frem aliphatic and aryl radicals containing a carboxyl group,and amides the nitrogen of I which is directly attached to an alkyl radical and the nitrogen of which is directly attached to an aryl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, and amides the nitrogen of which is directgroup consisting of amides the nitrogen of which is linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, amides the nitrogen of which is directly attached to an aryl radical and linked to a radical selected from 5 aliphatic and aryl radicals containing a 'carboxyl group, and amides the nitrogen 01' which is directly attached to an alkyl radical and linked to a radical selected from aliphatic and aryl radicals containing a carboxyl group, and an alkali 10 sulflte.

' KARL KUMETAT.

SEBASTIAN GAS8NER.' 

